Title: Physical pictures of transport in heterogeneous media: Advection-dispersion, random-walk and fractional derivative formulations 
Resource Type: document --> technical publication --> journal article 
Country: EU Projects 
Year: 2002 
Availability: Water Resources Research 38(10), 1191, doi:10.1029/2001WR001030 
Author 1/Producer: Berkowitz, B 
Other Authors/Producers: Klafter, J Metzler, R & Scher, H 
Author / Producer Type: University research group / research institute 
Publisher: American Geophysical Union 
Publisher City: 2000 Florida Avenue N.W. Washington, DC 20009 USA 
ISSN: 0043-1397 
Article Weblink (=direct link): http://www.agu.org/pubs/crossref/2002/2001WR001030.shtml  
EUGRIS Keyword(s): Contaminated land-->Risk assessment-->Exposure pathways
Groundwater protection-->Groundwater protection overview
Groundwater protection-->Planning-->Modelling
Soil-->Processes
Soil-->Soil Overview
Water resources and their management -->Water resources and their management Overview
 
Short description: The paper examines the technical basis for the development of transport equations in porous media. The application of these equations is focused on accounting for the appearance of non-Fickian (anomalous) transport behavior. The general ensemble-averaged transport equation is shown to be equivalent to a continuous time random walk (CTRW). Fractional derivative formulations of the transport equations, both temporal and spatial, emerge as special cases of the CTRW. The use in this context of Lévy flights is also examined. To determine chemical transport in field-scale situations, the CTRW approach is generalized to nonstationary systems. 
Submitted By: Dr Stefan Gödeke WhoDoesWhat?      Last update: 15/05/2007